Caring for fish in a container water garden is easy and much the same as an in-ground pond. First be sure the container you choose will be an adequate size for the fish. An 18-inch diameter or about a 25 gallon sized container can handle 2-3 fish. Among the popular varieties like goldfish and koi (Japanese carp), you might also enjoy platys, guppies and mollies. Gambusa fish will eat mosquito larvae. These are some of the varieties best suited to the changing water temperatures found in container water gardens.
Before introducing your new fish to your container give the water 2 weeks to stabilize and for any chlorine in the water to evaporate. Allow your new fish to acclimate to your container’s water temperature by floating the fish in the bag provided by the pet store on the waters surface for 20 minutes during the morning or evening when the container is shaded. Feed the fish lightly with goldfish food, over time the fish will feed on small amounts of algae that will form in the water.